CVE-2025-66303
MediumCVSS 4.9Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
In Grav prior to 1.8.0-beta.27, a Denial of Service (DoS) vulnerability exists related to the handling of the scheduled_at parameter. The application fails to properly sanitize cron expressions, allowing an attacker to render the admin panel non-functional by manipulating the parameter, such as with a single quote.
Risk Assessment
An attacker could disable the admin panel, causing significant disruption to administrative operations. Recovery requires manual intervention on the server.
Recommendation
Update Grav to version 1.8.0-beta.27 or later. Implement validation and sanitization of the scheduled_at parameter to prevent injection of malicious cron expressions.
Other vulnerabilities in Grav
See all- CVE-2026-109326High
Grav before 2.1.7 contains an information disclosure vulnerability because bundled nginx, lighttpd, IIS, and Caddy 2 configurations block .git only at document root. Unauthenticated attackers can request nested repositories such as user/.git to retrieve Git config, refs, and objects, reconstructing unpublished history or committed secrets.
- CVE-2026-100668Medium
Grav 2.0.0 through 2.0.24 contain a Twig content sandbox escape. The `array` filter is allowlisted but lacks the sandbox guard, allowing access to the raw DI container and disclosure of the full configuration tree, including credentials and secrets, to anonymous visitors.
- CVE-2026-44738High
Grav is a file-based web platform. Prior to version 2.0.0-rc.2, the Twig sandbox allow-list permitted any user with the admin.pages role to call config.toArray() within a page body, dumping the entire merged site configuration, including all plugin secrets.
- CVE-2026-42611High
Grav is a file-based web platform. Prior to version 2.0.0-beta.2, a low-privileged user could inject an svg element, leading to an XSS attack that could escalate to dumping system information available under /admin/config/info when a Super Admin visits the page.
- CVE-2026-75837Critical
Grav before 2.0.14 fails to guard the access field in the core group blueprint with the required security@: admin.super restriction. A delegated admin.users operator can save a group with access[admin][super]=true to escalate to super-admin, gaining scheduler and Twig evaluation capabilities.
- CVE-2026-65008Critical
Grav 2.0.4 (fixed in 2.0.7) contains a remote code execution vulnerability in Blueprint::dynamicData(). The function passes a Class::method callable string and its arguments directly to call_user_func_array() without any allowlist. Because the form plugin routes page frontmatter through this path, an authenticated account with admin.pages (or api.pages.write) permission can plant a malicious callable directive in a page. The command executes as the web-server user whenever anyone – including an unauthenticated visitor – accesses the page.
- CVE-2025-66844Critical
In grav before 1.7.49.5, a SSRF (Server-Side Request Forgery) vector may be triggered via Twig templates when page content is processed by Twig and the configuration allows undefined PHP functions to be registered.
- CVE-2025-66301Critical
Grav is a file-based Web platform. Prior to 1.8.0-beta.27, due to improper authorization checks when modifying critical fields on a POST request to /admin/pages/{page_name}, an editor with only permissions to change basic content on the form is now able to change the functioning of the form through modifying the content of the data[_json][header][form] which is the YAML frontmatter which includes the process section which dictates what happens after a user submits the form which include some important actions that could lead to further vulnerabilities. This vulnerability is fixed in 1.8.0-beta.27.
- CVE-2026-109325High
Grav from 2.0.22 before 2.1.7 contains an authentication bypass vulnerability in the Clockwork profiler that trusts loopback REMOTE_ADDR values. Unauthenticated attackers behind a same-host HTTP proxy can read profiler records exposing system and plugin configuration, secrets, request metadata, and queries.
- CVE-2026-109324Medium
Grav before 2.1.7 contains a denial of service vulnerability that allows authenticated media authors to exhaust memory by uploading compressed oversized raster images. Attackers can reference a Twig or Markdown transform so GD or Imagick decodes the full source without dimension checks, letting anonymous requests repeatedly cause page unavailability.
Original NVD description (English source)
Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

